Interpretive Summary: The International Rules of Botanical Nomenclature, under which fungi are also classified, require a preserved specimen, the type specimen, for all described species. The yeast Wickerhamomyces anomalus is common in nature and widely used for the biocontrol of spoilage fungi that contaminate ensiled grain. W. anomalus is also gaining importance in biotechnology. It was discovered that there is no valid type specimen for W. anomalus, but there are type specimens for each of two obscure yeasts that were described at about the same time as W. anomalus. Based on gene sequence comparisons, the two obscure yeasts are the same species as W. anomalus and according to the nomenclatural code, one of those names should be used in preference to W. anomalus. In order to prevent confusion to more than 60 years of research because of a name change, this manuscript proposes to conserve the species name ‘anomalus’, which will be based on NRRL Y-366 as the type specimen.

Technical Abstract:
The International Rules of Botanical Nomenclature, under which fungi are also classified, require a preserved specimen, the type specimen, for all described species. The yeast Wickerhamomyces anomalus, which is common in nature and widely used for the biocontrol of spoilage fungi that contaminate ensiled grain, was described without the clear designation of a type strain. Based on D1/D2 large subunit rRNA and ITS gene sequence comparisons, two obscure yeasts are the same species as W. anomalus and according to the nomenclatural code, one of those names should be used in preference to W. anomalus. In this manuscript, we propose to conserve the species name ‘anomalus’, which will be based on NRRL Y-366 as the type specimen.